1. Field
The present invention relates generally to handling roaming lists in a wireless communication system, and more specifically to updating a preferred roaming list and to coordinating different protocol versions between a wireless communication network and remote users.
2. Background
Protocols are regulations that govern the transmission and receipt of information across a data communications link. Protocols are detailed in a set of standards that assures that different network products can work together. Any product using a given protocol should work with any other product using the same protocol. In a wireless communication system, protocols define the various architectural layers of the system. As protocols and standards are revised, those system components using an older version of the protocols and standards may become incompatible with those having newer capabilities. A variety of methods are used to overcome such incompatibility, wherein each fix is specific to a protocol and/or standard.
One area of incompatibility often occurs when protocols governing traditionally voice-dominated communications are expanded to also govern high data rate transmissions. For example, a remote user of one service provider, the home provider, may have access to other service providers, the foreign provider, when outside the service area of the home provider. The process is called roaming, and is facilitated by the use of roaming lists maintained by the remote user. The roaming list is updated by the service provider as the list changes, e.g., a new relationship with another service provider. The format of the roaming list as well as the format of the transmissions to update the roaming list may be specified by protocols in a standard. The addition of high data rate services, or other new services, may require changes in format to the roaming list as well as changes in the method of updating the roaming list. Such revisions to the protocol may cause incompatibility difficulties between the network and remote users. When the protocol revision of the remote user is different from that of the network, the accuracy and availability of the roaming list to the remote user may be jeopardized.
There is, therefore, a need in the art for an efficient procedure to configure, maintain and update preferred roaming lists over different transmission protocol versions in a wireless communication system.